The UGTT, Tunisia's trade union federation, called the strike in protest at the murder of Chokri Belaid on Wednesday. It will be the first such strike since 1978 and there is now deep uncertainty and anxiety about how events will unfold.

Belaid, a secular, leftist human rights lawyer, was shot dead at close range on his way to work in an attack that was condemned by the government, blamed on extremists but claimed by nobody. The assailant fled on a motorbike pillion.